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Stability analysis of a dike constructed of anthropogenic materials
PublicationNumerical analyses of stability are presented for a hypothetical dikes constructed of dredged materials and bottom ash, in varying proportions. The paper is related to the international research project DredgDikes, which focused on the use of anthropogenic materials in dikes construction and flood protection. The aim of this project was to investigate the possibility of using anthropogenic materials from rivers and sea dredging...

The buckling analysis of a coldformed steel Csectional column resting on an elastic foundation
PublicationThe paper is focused on stability analysis of different models of steel coldformed Csection column. The analysed element may be applied as a primary loadbearing member in steel trusses or silo columns. The column can be used as a support for a wall of roof plates made of corrugated sheets. The wall sheeting that restrains the column against buckling may be considered as an elastic foundation. Due to the design solutions the...

Frequency and time domain characteristics of digital control of electric vehicle inwheel drives
PublicationInwheel electric drives are promising as actuators in active safety systems of electric and hybrid vehicles. This new function requires dedicated control algorithms, making it essential to deliver models that reflect better the wheeltorque control dynamics of electric drives. The timing of digital control events, whose importance is stressed in current research, still lacks an analytical description allowing for modeling its...

Simulations of air and water flow in a model dike during overflow experiments
PublicationFlow in flood dikes, earth dams, and embankments occurs in variably saturated conditions, with pores of the earth material filled partly with water and partly with air. In routine engineering analysis, the influence of pore air is neglected and the air pressure is assumed equal to atmospheric. In some circumstances, for example, during overtopping of the dike by water, the effect of pore air on water flow and stability of the structure...

Distortional buckling of composite thinwalled columns of a boxtype cross section with diaphragms
PublicationDistortional buckling of axially compressed columns of boxlike composite cross sections with andwithout internal diaphragms is investigated in the framework of onedimensional theory. The channel membersare composed of unidirectional fibrereinforced laminate. Two approaches to the member orthotropic materialare applied: homogenization based on the theory of mixture and periodicity cells, and homogenization basedon the Voigt–Reuss...

Mobile Laser Scanning Calibration on a Marine Platform
PublicationThe article describes the method of calibration of the Riegl VMZ400 mobile scanning system on a floating platform and an experiment aimed at conducting measurements from a previously calibrated instrument. The issue of factors affecting the quality of measurements was discussed. Mobile laser scanning is an increasingly popular measurement solution, but it is still innovative on a European scale. The use of a floating platform...

TRUSS JOINT WITH POSITIVE ECCENTRICITY EXPERIMENTAL RESEARCH
PublicationDue to the technological reasons in modern lightweight steel trusses, fabricated from cold formed sections, positive eccentricities appear in the truss nodes what induce additional forces in the truss chords. To account for the real loadcarrying capacity of truss node area the steel structure research in scale 1:1 were conducted. The experiments consisted of two parts: preliminary and proper one, when conclusions from...

MODELOWANIE MATEMATYCZNE PRZEGRÓD LODOWYCH
PublicationW celu ochrony przed niebezpiecznym zjawiskiem zatoru lodowego opracowano szereg metod, które można podzielić na metody czynne i bierne. Pierwsza grupa obejmuje działania techniczne prowadzące do mechanicznego lub termicznego usuwania lodu i neutralizacji zatorów. Wykorzystuje się w tym calu głównie lodołamacze lub innego typu jednostki pływające. Do metod biernych zalicza się przede wszystkim przegrody lodowe budowane w celu stabilizacji...

Spatial pattern of ASGEUPOS sites
PublicationThe article presents the spatial pattern analysis of the ASGEUPOS permanent GNSS stations in Poland. Using different methods and tools (nearest neighbour, Riplay’s Kfunction, morphology of Thiessen polygons) we proved that the station distribution model changes within scales. At short distances up to 65 km, which are typical lengths in the network, stations are irregularly dispersed. Increasing this distance to 130 km and over...

Numerical Issues and Approximated Models for the Diagnosis of Transmission Pipelines
PublicationThe chapter concerns numerical issues encountered when the pipeline flow process is modeled as a discretetime statespace model. In particular, issues related to computational complexity and computability are discussed, i.e., simulation feasibility which is connected to the notions of singularity and stability of the model. These properties are critical if a diagnostic system is based on a discrete mathematical model of the flow...

NEW DESIGNS OF CENTRIFUGAL MAGNETIC FLUID SEALS FOR ROTATING SHAFTS IN MARINE TECHNOLOGY
PublicationThe centrifugal magnetic fluid seals have important advantage over the conventional centrifugal seals. They maintain very good sealing capacity at static, medium and high speeds of shaft rotation, with the increased seal lifetime, and minimum torque and static friction. These seals are particularly useful in cases when the angular shaft velocity varies and sometimes decreases to nearly or exactly zero, such as in flywheel applications,...

ROZPRAWA DOKTORSKA. Rodzina elementów hybrydowomieszanych w 6parametrowej teorii powłok, analiza geometrycznie nieliniowa powłok o funkcyjnej zmienności materiału wzdłuż grubości
PublicationW rozprawie opracowano rodzinę 4–węzłowych hybrydowo–mieszanych elementów skończonych w ramach nieliniowej 6–parametrowej teorii powłok, w której szóstym stopniem swobody jest obrót owinięcia. Elementy mieszane i częściowo mieszane sformułowano na podstawie odpowiednio podstawowego i autorsko zmodyfikowanego trójpolowego funkcjonału Hu–Washizu. W pracy zastosowano oryginalną interpolację niezależnych pól niesymetrycznych odkształceń...

Stability of roof trusses stiffened by corrugated sheets
PublicationThe present parametric study is devoted to the stability analysis of a set of trusses stiffened by decking of corrugated steel sheets. For different parameters of corrugated sheets the critical loading of the roof is calculated. In the parametrical analysis the threshold bracing condition of the roof is obtained. Then the geometrically nonlinear analysis of trusses braced by corrugated sheets was conducted. As a results of nonlinear...

Large thermoelastic displacement and stability FEM analysis of multilayered plates and shells
PublicationThe paper concerns the load capacity analysis of thermally loaded multilayered plates and shells. The multilayered body is treated as an equivalent single layer whose kinematics is consistent with first order shear deformation theory. The authors focus on the thermoelastic stability problem of the thinwalled structures. The equilibrium paths are traced with the use of RiksWempnerRamm algorithm. By making use of the TsaiWu...

Stability of softly switched multiregional dynamic output controllers with a static antiwindup filter: A discretetime case
PublicationThis paper addresses the problem of modelbased global stability analysis of discretetime Takagi–Sugeno multiregional dynamic output controllers with static antiwindup filters. The presented analyses are reduced to the problem of a feasibility study of the Linear Matrix Inequalities (LMIs), derived based on Lyapunov stability theory. Two sets of LMIs are considered candidate derived from the classical common quadratic Lyapunov...

Geometrically nonlinear FEM analysis of FGM shells based on neutral physical surface approach in 6parameter shell theory
PublicationThe paper presents the formulation of the elastic constitutive law for functionally graded materials (FGM) on the grounds of nonlinear 6parameter shell theory with the 6th parameter being the drilling degree of freedom. The material law is derived by throughthethickness integration of the Cosserat plane stress equations. The constitutive equations are formulated with respect to the neutral physical surface. The influence of...

Buckling of thinwalled columns accounting for initial geometrical imperfections
PublicationThe paper is devoted to the effect of some geometrical imperfections on the critical buckling load of axially compressed thinwalled Icolumns. The analytical formulas for the critical torsional and flexural buckling loads accounting for the initial curvature of the column axis or the twist angle respectively are derived. The classical assumptions of theory of thinwalled beams with nondeformable crosssections are adopted. The...

Simplified stability analysis of steel cylindrical silos with corrugated walls and vertical columns
PublicationIn the paper a simplified stability analysis of steel cylindrical silos composed of corru¬gated walls and vertical opensectional columns was proposed. The whole 3D silo was modeled as a single column resting on elastic foundation provided by the silo walls. In proposed formula for the calculation of the foundation stiffness the curvature of the silo walls was taken into account. Three different analyses were carried out using...

A new approach of coastal cliff monitoring using Mobile Laser Scanning
PublicationThe article proposes a new approach of coastal cliff monitoring which bases on a new comprehensive monitoring system, being a combination of mobile scanning from the sea with the geotechnical stability analysis. Mobile laser scanning is an innovative solution for 3D data collection which allows the monitored object geometry to be precisely measured, thus providing opportunities for series of analyses contributing to the development...

Z type Observer Backstepping For Induction Machines
PublicationThis paper contains a relatively new synthesis method for nonlinear objects, named backstepping. This method can be used to obtain the observer structure. The paper presents the structure of the speed observer which is a new proposition of observer backstepping with additional state variables marked Z. The rotor speed can be estimated in three different ways. The first is based on the adaptive approach, the second on the nonadaptive...

Investigation of stability and limit load of a truss overhead opened bridge
PublicationThe paper presents selected methods of determining stability and limit load of a truss top chord in opened bridges. These methods include linear buckling and nonlinear static analysis based on the finite element method and algorithms based on design code procedures. The described methods were tested on an example of a steel footbridge situated in Straszyn. The results of stability analysis are compared. The results of geometrical...

Buckling Analysis of Cold Formed Silo Column
PublicationThe paper is devoted to stability analysis of different models of steel cold formed silo column. The steel cylindrical silos are often composed of corrugated walls and vertical opensectional columns uniformly placed along the silo circumference. Both the whole 3D silo, a simplified model consisting of one column with a part of the silo walls, and a single column resting on elastic foundation provided by the silo walls were analyzed....

Local buckling of composite channel columns
PublicationThe investigation concerns local buckling of compressed flanges of axially compressed composite channel columns. Cooperation of the member flange and web is taken into account here. The buckling mode of the member flange is defined by rotation angle a flange about the line of its connection with the web. The channel column under investigation is made of unidirectional fibrereinforced laminate. Two approaches to member orthotropic...

On local buckling of coldformed channel members
PublicationThe paper deals with local buckling of the compressed flanges of coldformed thinwalled channel beams subjected to pure bending or axially compressed columns. Arbitrarily shaped flanges of open crosssections and the webflange interactions are taken into account. Buckling deformation of a beam flange is described by displacement related to torsion of the flange about the line of its connection with the web. Total potential energy...

A comparison of structural and luminescence properties of lead(II) coordination polymers with isomeric thiophenecarboxylate ligands
PublicationTwo new lead(II) coordination polymers with isomeric thiophenecarboxylates, namely [Pb(2tpCOO)2]n (1) and [Pb(3tpCOO)2(H2O)]n (2) (2tpCOO− = thiophene2carboxylate, 3tpCOO− = thiophene3carboxylate), were synthesized and characterized. Single crystal Xray crystallography revealed a distorted pentagonal pyramidal geometry {PbO6} around Pb in 1 and a distorted dodecahedral geometry {PbO8} in 2. The distortion derived from the...

ENERGY ANALYSIS OF PROPULSION SHAFT FATIGUE PROCESS IN ROTATING MECHANICAL SYSTEM PART I TESTING SIGNIFICANCE OF INFLUENCE OF SHAFT MATERIAL FATIGUE EXCITATION PARAMETERS
PublicationThe article discusses the problem of mathematical modelling of energy conversion processes in a rotating mechanical system for the purpose of identifying fatigue states of propulsion shafts in this system. A simplified physical model of the analysed system, constructed in an appropriate scale, has made the basis for the experimental research. The research programme took into consideration mechanical fatigue excitation of the model...

SELECTED COMBINED POWER SYSTEMS CONSISTED OF SELFIGNITION ENGINE AND STEAM TURBINE
PublicationThis paper presents optimization of selected combined diesel enginesteam turbine systems. Two systems: the system combined with waste heat onepressure boiler only and its version containing additionally lowpressure boiler proper feeding degasifier and the system of twopressure cycle, were taken into considerations. Their surplus values of power output and efficiency associated with utilization of waste heat contained in piston...

The propagation of the waves in the CTO S.A. towing tank
PublicationThe paper presents the results of research focused on the wave propagation in the CTO S.A. deepwater towing tank. In the scope of paper, the wavemaker transfer function was determined for regular waves, based on the Biésel Transfer Function and further for irregular waves, based on Hasselman model of nonlinear energy transfer. The phenomena: wave damping, wave breakdown and wave reflection, were measured, analyzed and mathematically...

INCREASING POWER SUPPLY SAFETY IN THE ASPECT OF SUPPORTING THE RENEWABLE ENERGY SOURCES BY CONVENTIONAL AND VIRTUAL POWER STORES
PublicationThis paper presents characteristics and purposefulness of supporting the renewable energy sources (OZE) by means of energy stores. The main emphasis was placed on analysis of virtual energy stores available for implementation in Polish economy conditions. A role which management of Demand Side Response (DSR) may play in balancing Polish electric power system, is discussed. Implementation of such solutions together with conventional...

Stable indirect adaptive control based on discretetime TS fuzzy model
PublicationThis paper presents an indirect adaptive fuzzy control scheme for uncertain nonlinear asymptotically stable plants.A discretetime TS fuzzy inputoutput model is employed to approximate the unknown plant dynamics. The TS fuzzy model is fed with its own states, which are indeed its past outputs, rather than the measurements from the plants. Entirely based on this model, a feedback linearization control law is designed by using...

Stable indirect adaptive control based on discretetime TS fuzzy model
PublicationThis paper presents an indirect adaptive fuzzy control scheme for uncertain nonlinear asymptotically stable plants.A discretetime TS fuzzy inputoutput model is employed to approximate the unknown plant dynamics. The TS fuzzy model is fed with its own states, which are indeed its past outputs, rather than the measurements from the plants. Entirely based on this model, a feedback linearization control law is designed by using...

Analysis of a gene expression model
PublicationWe study a mathematical model of gene transcription and protein synthesis with negative feedback. We consider a system of equations taking into account the number of active binding sites, the way in which dimers bind to DNA and time delay in translation process. For a simplified model that consist of three ordinary differential equations with time delay we derive conditions for stability of the positive steady state and for the...

Control system for contactless electrical energy transfer with varying air gap
PublicationInductive power transfer (IPT) is a system by which electrical energy may be transmitted without electrical connection through a large air gap between coils. Systems usually considered in the literature are the ones with a constant air gap. The paper describes the analysis of IPT, which allows for supplying an electrical load in the conditions of slow, in relation to the dynamics of power supply, changes in the dimensions of the...

Mathematical analysis of a generalised p53Mdm2 protein gene expression model
PublicationWe propose the generalisation of the p53Mdm2 protein gene expression model introduced by Monk (2003). We investigate the stability of a unique positive steady state and formulate conditions which guarantee the occurrence of the Hopf bifurcation. We show that oscillatory behaviour can be caused not only by time lag in protein transcription process, but also can be present in the model without time delay. Moreover, we investigate...

Reliability assessment of an OVH HV power line truss transmission tower subjected to seismic loading
PublicationThe study focuses on the reliability of a transmission tower OS24 ON150 + 10, an element of an OVH HV power line, under seismic loading. In order to describe the seismic force, the reallife recording of the horizontal component of the El Centro earthquake was adopted. The amplitude and the period of this excitation are assumed random, their variation is described by Weibull distribution. The possible space state of the phenomenon...

Numerical Test for Stability Evaluation of DiscreteTime Systems
PublicationIn this paper, a new numerical test for stability evaluation of discretetime systems is presented. It is based on modern rootfinding techniques at the complex plane employing the Delaunay triangulation and Cauchy's Argument Principle. The method evaluates if a system is stable and returns possible values and multiplicities of unstable zeros of the characteristic equation. For statespace discretetime models, the developed test...

STABILITY ANALYSIS OF A TRUSS WITH SLOPING ELASTIC BRACES
PublicationSteel trusses have a much greater strength and stiffness in their plane than out of their plane, and therefore should be braced against lateral deflection and twisting. Such elements like purlins apart from bearing vertical load are part of bracing that stabilize roof trusses against distortional buckling. The stability of trusses with elastic bracing was investigated in an experimental research. Braces situated at some angle measured...

Stability analysis of multilayered composite shells with cutouts
PublicationW pracy analizowana jest stateczność ściskanej osiowo kompozytowej powłoki warstwowej. Badany jest wpływ usytuowanego centralnie w powłoce kwadratowego otworu na stateczność konstrukcji. Obliczenia wykonano w programie NXNastran (wersja 6.0). Poziom obciążeń krytycznych wyznaczony został w rozwiązaniu liniowym (liniowy problem własny) oraz na drodze analizy przyrostowej z uwzględnieniem dużych przemieszczeń (statyka nieliniowa)....

Stability analysis of cylindrical composite shells in MSC/Nastran
PublicationW pracy badane jest zastosowanie systemu MSC/NASTRAN for Windows do analizy stateczności kompozytowych powłok cylindrycznych. Przeprowadzono obliczenia dla dwóch wybranych przykładów paneli cylindrycznych poddanych równomiernemu ściskaniu w kierunku tworzącej dokonując analizy zarówno w zakresie stateczności początkowej jak i problemu geometrycznie nieliniowego w procesie przyrostowym. Otrzymane wyniki w pełni potwierdziły bogate...

Czesław Szymczak prof. dr hab. inż.
People 
Stability analysis of a road scarp in the Carpathian Mountains and methods of its protection
PublicationThe purpose of the study was to analyse the stability of a road scarp endangered by a landslide and to consider some measures for its stabilization. The potential landslide could unfavourably alter the shape of the slope, thus a religious sanctuary situated above the slope. The present research has resulted in suggestions of possible protection methods, namely, drainage, soil nailing, installation of piles, supporting the scarp...

Stability analysis of twostep RungeKutta methods for delay differential equations
PublicationW pracy badana jest własność stabilności dwukrokowej metody RungegoKutty względem liniowego równania testowego o zespolonych współczynnikach. Udowodniono, że jeśli pewne warunki są spełnione to każda Astabilna dwukrokowa metoda RungegoKutty zastosowana do równania różniczkowego z opóźnieniem jest Pstabilna.

Comparison of classical Winter's bracing requirements of compressedtruss chord with stability analysis of 3D trussmodel
PublicationMost code requirements concerning bracing are based on principles developed by Winter. The present research is devoted tostudy a lateral buckling of truss with linear elastic side supports. The classical Winter's model of truss chord in the case ofout of the truss plane buckling is compared with nonlinear analysis of 3D truss model. Full bracing condition, that permitsthe truss chord to support load level corresponding to an unbraced...

Stateczność czołowego obwałowania nasypu przeciwpowodziowego Jeziora Druzno
PublicationPrzedstawiono analizę stateczności czołowego obwałowania przeciwpowodziowego Jeziora Druzno w miejscowości Nowe Dolno. Obliczenia przeprowadzono zarówno w naprężeniach całkowitych jak i efektywnych uproszczoną metodą Bishopa oraz metodą FelleniusaPeterssona. Uzyskano wysokie wartości minimalnego wskaźnika stateczności, zapewniające znaczny zapas stateczności nasypu podczas długotrwałych piętrzeń wody w jeziorze. Mogłoby to wskazywać...

Stability analysis of the internal cylindrical shell wall of a vertical double shell tank under a water test.
PublicationPrzedstawiono analizę zagrożenia stateczności lokalnej płaszcza wewnętrznego przy różnicy poziomów wody w zbiorniku wewnętrznym i przestrzeni międzypłaszczowej podczas próby wodnej zbiornika. Podano krytyczne różnice poziomów wody dla typowych zbiorników o pojemności od 10 000 do 100 000 m3.

Ireneusz Kreja dr hab. inż.
PeopleGraduated from the mathematical class at the Nicolaus Copernicus High School in Gdańsk (1974). Master of Sciences in Civil Engineering after studies at Gdansk University of Technology (GUT), Poland (19741979). Since 1979 became an employee of GUT. In 1989 earned PhD degree in Civil Engineering (with grade "Summa cum Laude") from GUT. In 2008 obtained D. Sc. (Habilitation) degree in Civil Engineering (with grade "Summa cum Laude")...

Paweł Michał Bielski mgr inż.
People 
Synteza bezczujnikowego sterowania maszyną indukcyjną klatkową zasilaną z falownika prądu
PublicationSynteza bezczujnikowego sterowania maszyną indukcyjną klatkową zasilaną z falownika prądu stanowi cel niniejszej monografii. Praca zawiera podstawowe informacje na temat modelowania układu napędowego z maszyną indukcyjną klatkową zasilaną z falownika prądu. Przedstawiono informacje na temat linearyzacji nieliniowych obiektów. Na podstawie metody syntezy strukturalnej opracowano nowe transformacje do postaci zmiennych multiskalarnych,...

Krzysztof Jan Kaliński prof. dr hab. inż.
PeopleKrzysztof J. Kaliński completed his MSc study at Gdańsk University of Technology (GUT) Faculty of Production Engineering (1980, result – get a first). He obtained PhD at GUT Faculty of Machine Building (1988, result – get a first), DSc at GUT Faculty of Mechanical Engineering (ME) (2002, result – get a first), and professor’s title – w 2013 r. In 2015 r. he became full professor.His research area includes: theoretical and applied...

Effect of vehicle motion stability after impact/crash on traffic safety
PublicationThe article presents the application of general stability theory to the study of road traffic stability immediately after an impact (crash, collision). It turns out that when modelling a collision, vehicles can be treated as colliding masses and dynamical systems can be assigned to this phenomenon.